First you wrote "delete" and later uninstall. The number of folk getting into trouble by deleting software by deleting folders and files is legendary. Always try the uninstall route and then reboot even if it doesn't ask you to.
Then it should be ready for the next title.
I want to change from Comodo Pro free to Online Armor Personal Firewall free. I'm planning on downloading Online Armor, then deleting Codmodo and installing Online Armor. My questions are:
Is this the right way to change?
If I uninstall Comodo from add/remove programs, will I need to clean up any files after?